Form fitting lightweight container cover

ABSTRACT

A lightweight form fitting container cover having a top surface, a bottom surface, and an integrally formed rim projecting downwardly from the bottom surface and defining an interior space within the rim, and further having at least one layer of deformable foam inserted into the interior space within the rim for a form fit over the upper rim of a container.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 60/173,047, filed Dec. 24, 1999.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates generally to container and tank covers, and more particularly to a lightweight container cover having a foam filled interior space for snuggly fitting on the rim of a wide variety of container.

[0004] 2. Description of the Prior Art

[0005] The field of lids for vessels is crowded, particularly as it pertains to lids that provide a leak proof fit and seal. In some applications, however, when a water-tight seal is not required, and further when the vessel is constructed of heavy and/or fragile materials, such that handling the vessel lid is difficult and requires careful handling, when the vessel is adapted to stand upright and has a top opening only, and when access to the vessel interior is only occasionally required, it may be preferable to have a tightly fitting lid that may be easily removed, easily handled, and easily replaced. These conditions and circumstances apply to toilet tanks and toilet tank lids, as is well known.

[0006] The typical toilet tank lid matches the material and relative costs of the tank and toilet to which it belongs. Accordingly, toilet tank lids are generally made of a heavy ceramic or similar material. They are heavy, unwieldy, fragile, expensive, and rigidly fixed in size so that they can be seated on only one size and kind of tank (typically proprietary), and then usually only loosely. Moreover, ceramic lids frequently break and must be replaced.

[0007] Toilet tank lids seem to be peculiarly vulnerable to breakage and are a favorite target of vandals and clumsy people. Yet in many if not most states, a house or other dwelling cannot be rented or sold with an exposed toilet tank. Accordingly, there is a large demand for after market toilet tank lids, and many attempts have been made to provide a tank lid that overcomes the many undesirable features outlined above.

[0008] The most recent example is perhaps U.S. Pat. No. 5,913,612 to Turner, which discloses a plastic replaceable tank cover having sides, a lip around the sides, and a resilient restraining device installed on the bottom surface of the lid that has spring arms movable in a plane generally parallel to the bottom surface of the lid for resiliently pressing against the inside surface of the toilet tank wall, thereby clamping the tank wall between the lip and spring arms.

[0009] While the tank lid disclosed in the '612 patent solves many of the problems of tank lids generally, the tank lid disclosed therein still suffers a few defects: first, it is adapted to fit only one size of tank; and second, it involves several moving parts. The device itself is complex, as is its manufacture. This liability applies equally to earlier advances in the art, including: U.S. Pat. No. 2,238,699 to Levine, which discloses an adjustable cover for flush tanks; U.S. Pat. No. 4,162,548, to Groombridge et al, which discloses a lightweight water closet shell comprising monolithic molded plastic basin and cistern components; U.S. Pat. No. 3,760,428 to Korol, which teaches a water closet tank formed of molded plastic and having a lid with interlocking keys and tabs which engage complementary grooves in the tank; and U.S. Pat. No. 2,745,110 to Lyster, Jr., which discloses a locking cover for toilet flush tanks.

[0010] There remains a need for an easily handled, lightweight tank lid that fits and seats securely on a wide variety of toilet tanks or other similarly constructed liquid-containing vessels.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a perspective view of a first preferred embodiment of the form fitting lightweight container cover of the present invention, shown relative to a complementary tank;

[0012]FIG. 2 is a perspective view of the underside of the lid of FIG. 1;

[0013]FIG. 3 is a perspective view of the underside of the container cover of the present invention, shown embodied as a toilet tank cover;

[0014]FIG. 4 is a cross-sectional side view in elevation of the lid of FIG. 3;

[0015]FIG. 5 is a cross-sectional side view of an alternative embodiment of the present invention, showing the lid having only a perimeter layer of deformable foam;

[0016]FIG. 6 a cross-sectional side view in elevation of the container cover of the present invention depicting the cover having a two layers of differentially deformable foam; and

[0017]FIG. 7 is a cross-sectional side view in elevation of the inventive cover, showing an embodiment having an upper rim for containing objects placed on the cover's upper surface.

SUMMARY OF THE INVENTION

[0018]FIG. 1 is a perspective view of a first preferred embodiment of the form fitting lightweight container cover of the present invention, shown relative to a complementary tank, and FIG. 2 is a perspective view of the underside of the lid of FIG. 1. These views show that the form fitting lightweight container cover of the present invention, generally denominated 10, comprises a lightweight lid 12 having a top surface 14, a bottom surface 16, and an integrally formed rim 18 projecting downwardly from said bottom surface, said rim having an exterior side 20 and an interior perimeter 22 and defining an interior space 24 or cavity within the boundary or interior perimeter of the rim. The lid is preferably fabricated from rigid lightweight plastic, and more preferably molded plastic. As illustrated in FIGS. 1 and 2, the interior perimeter 22 of the interior space of the lid is generally designed with dimensions slightly in excess of the dimensions of the upper rim 26 of the vessel 28 for which it is intended as a cover. When embodied as a toilet tank cover, as shown in FIGS. 3 and 4, it may be shaped and sized to fit the specific proprietary dimensions of the upper rim of the toilet tank.

[0019] As illustrated in FIGS. 4, 5, and 7, at least one layer 30 of any one of a number of suitable thermosetting foam resins, or a combination of more than one of such resins, is inserted as a preformed sheet, or is poured or molded into the interior space adjacent to, and preferably bonded with, the rim and the bottom surface, and is then allowed to set until hardened so as to extend and expand the effective width of the rim. However the foam is placed into the interior space, it comprises a deformable foam region or border 32 that deforms in response to a firm placement on the rim of the top of the toilet tank to form a channel into which the tank rim tightly fits. That is, when the user wishes to fit and secure the tank cover on a tank or vessel, he or she simply centers or fits the cover as desired and presses firmly down on the cover to deform the foam border into a form fit on the tank rim. Channels will be formed in the foam to perfectly mate with the interior and exterior side surfaces of the tank to secure the cover firmly. The cover will not wobble or move about, will not rattle, and will prevent and resist a significant amount of water leakage.

[0020]FIG. 6 shows the cover having a first layer 34 and a second layer 36 of foam. Depending upon the intended application, only one or both of the layers may be deformable. Alternatively, only one layer may be deformable while the second is resilient and assumes its original shape after deformation under pressure. In either embodiment, having one or two or more layers, the foam provides both a

[0021] As depicted in FIG. 5, the foam border may constitute a frame or border 38 which itself defines an interior space in which there is no foam. Alternatively, as shown in FIGS. 2, 3, 4, 6, and 7, the foam region may entirely fill the space interior to the cover rim. The latter design provides the desirable feature of sound attenuation. Thus, mechanical sounds connected with toilet flushing are somewhat dampened by the preferred embodiment of the tank cover of the present invention.

[0022]FIG. 7 illustrates a container cover having an upwardly extending rim 42 to contain objects placed on top of the cover.

[0023] Materials suitable for use as the foam layer include any of a number of three-dimensional porous materials having a reticulated or latticelike configuration in cross section and which is pliable and conformable. Examples include open cell polyurethane foams, PVA foam, HYPOL foam, insulating foam for pipes, and structural buoyancy foams used in fiberglass boat manufacture, though the most desirable foam material for deformable foam is expanded polystyrene (EPS) foam having a chemical formula of (C₈H₈)n, with flame retardant additive. The preferred material for a second, non-deformable layer is STYROFOAM®, a product in the polystyrene family. [STYROFOAM is a registered trademark of The Dow Chemical Company, Midland, Miss.] Densities at or around two pounds per cubic foot (2 pcf) have been shown to particularly effective, though less dense and more dense foams may be used, particularly in the range of 0.5 to 4.0 pcf. The foam itself may bond to the tank cover at the time of manufacture, or, alternatively, an adhesive material 40 (FIG. 7) may be applied to the tank cover and/or foam to bond the foam to the cover's underside interior surfaces.

[0024] In certain applications, for example hospitals, it may be desirable to inhibit the growth of microrganisms on toilet surfaces. To that end, either before fitting the cover to the tank or after, the foam border or region may be coated with a thin film of nonporous material for easy cleaning. 

What is claimed as invention is:
 1. A lightweight form fitting container cover, comprising: lightweight lid having a top surface, a bottom surface, and an integrally formed rim projecting downwardly from said bottom surface and defining an interior space within said rim; at least one layer of deformable foam inserted into the interior space within said rim.
 2. The lightweight form fitting container cover of claim 1 , wherein said lid is fabricated from rigid lightweight plastic.
 3. The lightweight form fitting container cover of claim 2 , wherein said cover is made from injection molded plastic.
 4. The lightweight form fitting container cover of claim 1 wherein said at least one layer of deformable foam is fabricated of a thermosetting foam resin.
 5. The lightweight form fitting container cover of claim 5 , wherein said thermosetting foam resin is selected from the group consisting of open cell polyurethane foams, PVA foam, HYPOL foam, pipe insulation foam, and structural buoyancy foams used in fiberglass boat manufacture, or any combination of these.
 6. The lightweight form fitting container cover of claim 5 wherein said thermosetting foam resin is expanded polystyrene foam having a chemical formula of (C₈H₈)n.
 7. The lightweight form fitting container cover of claim 6 wherein said EPS has a density in the range of 0.5 to 4.0 pcf, inclusive.
 8. The lightweight form fitting container cover of claim 1 wherein said at least one deformable foam layer is inserted as a preformed sheet.
 9. The lightweight form fitting container cover of claim 1 wherein said at least one deformable foam layer is poured into the interior space defined by said rim and allowed to set until hardened.
 10. The lightweight form fitting container cover of claim 1 , further including a second layer of thermoplastic resin interposed between said deformable foam layer and said bottom surface of said container cover.
 11. The lightweight form fitting container cover of claim 10 wherein said second layer of thermoplastic resin is made of STYROFOAM.
 12. The lightweight form fitting container cover of claim 1 wherein said deformable foam layer is attached to said cover with adhesive. 